In the field of industrial marinating of meat products, it is known to use “tumblers”. A tumbler of this nature comprises a movable drum, or a stationary drum containing agitators, into which some of the meat which is to be treated is placed together with a quantity of substantially pulverulent marinade. As a result of the drum being set in motion, the meat comes into contact with the marinade, and the meat is marinated from the outside. These known tumblers have a number of drawbacks. For example, one drawback is that this is a batch process, so that this method of marinating cannot in fact be efficiently incorporated in a continuously operating treatment process for the meat products. One example of such processes is the slaughter of poultry, which currently takes place in a continuous process, with a very high capacity, with the aid of slaughtering installations which operate virtually automatically. Slaughtering installations of this nature supply a virtually constant flow of meat products, which continuity is essentially advantageous for downstream stations, for example continuous ovens and/or packaging stations. If the meat products then have to be marinated using a tumbler, this continuity has to be interrupted, which represents a drawback.
Furthermore, the marination in a tumbler is based in particular on mechanical interaction between the meat products which are present in the tumbler. This means that the amount of meat products must lie within specified limits in order to achieve the desired marination, and consequently the amount of meat in the tumbler cannot be varied as desired. When using a tumbler, the amount of additive which is placed in the tumbler also has to lie within specified limits in order to obtain the correct marination. The fact that both the amount of marinade and the amount of meat has to lie within a specified range in a tumbler results in the further effect, which is deemed to be disadvantageous, that the level of marinade added to the meat also lies within specified limits, usually between 5% and 8%. It is therefore not possible, for example when using a tumbler, to efficiently allow only a very small percentage of marinade to be added to the meat product if good distribution of the marinade in the product is also required. Also, the structure of the meat may be adversely affected by the mechanical action of the tumbler.
A further drawback of using a tumbler is that an excess of marinade builds up in cavities in the product and, considered in a broader sense, that undesirably large amounts of often expensive marinade are required, only a small fraction of which actually reaches the product which is to be treated.
Another known method for marinating (meat) products consists in guiding the product which is to be marinated through a liquid bath, the liquid in the bath having a marinating action. For example, a method is known in which air bubbles are introduced into the bath in order to set the marinade liquid in motion. However, this known method using a liquid bath does not allow integration with a continuous process for the production of meat products, such as integration with a slaughtering installation for poultry.